/* * scull.h -- definitions for the char module * * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet * Copyright (C) 2001 O'Reilly & Associates * * The source code in this file can be freely used, adapted, * and redistributed in source or binary form, so long as an * acknowledgment appears in derived source files. The citation * should list that the code comes from the book "Linux Device * Drivers" by Alessandro Rubini and Jonathan Corbet, published * by O'Reilly & Associates. No warranty is attached; * we cannot take responsibility for errors or fitness for use. * * $Id: scull.h,v 1.15 2004/11/04 17:51:18 rubini Exp $ */#ifndef _SCULL_H_#define _SCULL_H_#include <linux/ioctl.h> /* needed for the _IOW etc stuff used later *//* * Macros to help debugging */#undef PDEBUG /* undef it, just in case */#ifdef SCULL_DEBUG# ifdef __KERNEL__ /* This one if debugging is on, and kernel space */# define PDEBUG(fmt, args...) printk( KERN_DEBUG "scull: " fmt, ## args)# else /* This one for user space */# define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args)# endif#else# define PDEBUG(fmt, args...) /* not debugging: nothing */#endif#undef PDEBUGG#define PDEBUGG(fmt, args...) /* nothing: it's a placeholder */#ifndef SCULL_MAJOR#define SCULL_MAJOR 0 /* dynamic major by default */#endif#ifndef SCULL_NR_DEVS#define SCULL_NR_DEVS 4 /* scull0 through scull3 */#endif#ifndef SCULL_P_NR_DEVS#define SCULL_P_NR_DEVS 4 /* scullpipe0 through scullpipe3 */#endif/* * The bare device is a variable-length region of memory. * Use a linked list of indirect blocks. * * "scull_dev->data" points to an array of pointers, each * pointer refers to a memory area of SCULL_QUANTUM bytes. * * The array (quantum-set) is SCULL_QSET long. */#ifndef SCULL_QUANTUM#define SCULL_QUANTUM 4000#endif#ifndef SCULL_QSET#define SCULL_QSET 1000#endif/* * The pipe device is a simple circular buffer. Here its default size */#ifndef SCULL_P_BUFFER#define SCULL_P_BUFFER 4000#endif/* * Representation of scull quantum sets. */struct scull_qset {void **data;struct scull_qset *next;};struct scull_dev {struct scull_qset *data; /* Pointer to first quantum set */int quantum; /* the current quantum size */int qset; /* the current array size */unsigned long size; /* amount of data stored here */unsigned int access_key; /* used by sculluid and scullpriv */struct semaphore sem; /* mutual exclusion semaphore */struct cdev cdev; /* Char device structure*/};/* * Split minors in two parts */#define TYPE(minor)(((minor) >> 4) & 0xf)/* high nibble */#define NUM(minor)((minor) & 0xf)/* low nibble *//* * The different configurable parameters */extern int scull_major; /* main.c */extern int scull_nr_devs;extern int scull_quantum;extern int scull_qset;extern int scull_p_buffer;/* pipe.c *//* * Prototypes for shared functions */int scull_p_init(dev_t dev);void scull_p_cleanup(void);int scull_access_init(dev_t dev);void scull_access_cleanup(void);int scull_trim(struct scull_dev *dev);ssize_t scull_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos);ssize_t scull_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos);loff_t scull_llseek(struct file *filp, loff_t off, int whence);int scull_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);/* * Ioctl definitions *//* Use 'k' as magic number */#define SCULL_IOC_MAGIC 'k'/* Please use a different 8-bit number in your code */#define SCULL_IOCRESET _IO(SCULL_IOC_MAGIC, 0)/* * S means "Set" through a ptr, * T means "Tell" directly with the argument value * G means "Get": reply by setting through a pointer * Q means "Query": response is on the return value * X means "eXchange": switch G and S atomically * H means "sHift": switch T and Q atomically */#define SCULL_IOCSQUANTUM _IOW(SCULL_IOC_MAGIC, 1, int)#define SCULL_IOCSQSET _IOW(SCULL_IOC_MAGIC, 2, int)#define SCULL_IOCTQUANTUM _IO(SCULL_IOC_MAGIC, 3)#define SCULL_IOCTQSET _IO(SCULL_IOC_MAGIC, 4)#define SCULL_IOCGQUANTUM _IOR(SCULL_IOC_MAGIC, 5, int)#define SCULL_IOCGQSET _IOR(SCULL_IOC_MAGIC, 6, int)#define SCULL_IOCQQUANTUM _IO(SCULL_IOC_MAGIC, 7)#define SCULL_IOCQQSET _IO(SCULL_IOC_MAGIC, 8)#define SCULL_IOCXQUANTUM _IOWR(SCULL_IOC_MAGIC, 9, int)#define SCULL_IOCXQSET _IOWR(SCULL_IOC_MAGIC,10, int)#define SCULL_IOCHQUANTUM _IO(SCULL_IOC_MAGIC, 11)#define SCULL_IOCHQSET _IO(SCULL_IOC_MAGIC, 12)/* * The other entities only have "Tell" and "Query", because they're * not printed in the book, and there's no need to have all six. * (The previous stuff was only there to show different ways to do it. */#define SCULL_P_IOCTSIZE _IO(SCULL_IOC_MAGIC, 13)#define SCULL_P_IOCQSIZE _IO(SCULL_IOC_MAGIC, 14)/* ... more to come */#define SCULL_IOC_MAXNR 14#endif /* _SCULL_H_ */
